Joint bar for sectional tables



p 1949. P. ROSENBERG JOINT BAR FOR SECTIONAL TABLES 2 Sheets-Sheet 1 Filed March 25, 1947 44 Snuentor PH/ P ROSENBERG (Ittornegs p 1949- P. ROSENBERG 2,481,350

JdINT BAR FOR SECTIONAL TABLES 2 Sheets-Sheet 2 Filed March 25, 11947 ll V l I; 2 7 29 7 IE.

lhwentor PH/Z/P Rosa-M9526 %died I M v-zz/uzy (Ittornegs Patented Sept. 6, i949 I JOINT FOR SECTIONAL TABLES Philip Rosenberg, New York, N. Y., assignor to Universal Steel Equipment Corporation, New York, N. Y., a corporation of New York Application March 25, 1947, Serial No. 737,159

2 Claims.

This invention relates to joint structures for sectional work tables, more particularly to means for holding the surface material of adjacent table sections smoothly in place, and for bridging the space between the working surfaces of the adjacent sections.

The invention is disclosed herein as e bodied in a table structure of the kind disclosed in Letters Patent of the United States No. 2,327,743, granted to me on August 24, 1943, and is in the nature of an improvement upon the invention disclosed and claimed in said patent.

Tables of the kind referred to commonly include two or more sections,.each comprising a metallic frame having a plane metallic top portion and a non-metallic sheet of surfacing material adhered or otherwise suitably secured to the table top.

Because of the difference in thermal coefficients of expansion of the metallic and nonmetallic portions of the table, and also because the material of the surface sheet may be more or less hydroscopic in character while the metallic parts are not, there is a tendency for the surface sheet to creep and pull loose from the metallic portion of the table top, particularly at the ends of the table sections, and hence to'produce objectionable bulging or warping of the surface material at the joint between sections. It is a primary object of the present invention to provide an improved joint bar for obviating these drawbacks.

In Patent No. 2,327,743, disclosure is made of a joint bar having channels in its opposite sides at a short distance below the upper surface, each channel of just sufficient width'to receive and hold together a reduced end portion of the surface sheet and the immediately adjacent sheet metal portion of the table top. This construction obviated the need for hold-down screws, provided opposed holding members'under no substantial initial strain, and located the opposed holding surfaces so near to one another that changes of humidity and temperature could have no material tendency to impose strain upon the bar. While the head of the bar designed to lie in the rabbets for-med in the upper face of the surface material was continuous, the side portions of the body of the bar weremade discontinuous, being divided into a series of spaced-apart blocks. This construction. was provided because the metallic portion of the table top was composed of a series of adjacent channel members. The spaces between adjacent blocks were made wide enoughaso thatithe side walls of the channel and inturned flanges at the lower extremities of the side walls could extend in between adjacent blocks. The spaces between blocks were square-cut as shown in the patent.

The joint bar of the prior patent has proved to be very practical and satisfactory in useand has enjoyed a very substantial commercial suc cess. It has certain draw-backs and disadvantages, however, which it is the object of the present invention to eliminate. The bars had to be made one at a time, and when hollowed out rectangularly as shown in the patent involved rather expensive operations. Hollowing out to the extent illustrated in the patent, moreover, has been found to be unnecessary,'and indeed to lack advantages which can be realized if the spaces between blocks are formed. by a simple boring operation.

When the spaces are formed by boring, the minimum thickness of the block for accommodating the vertical flanges of the channel memhers is the same as before, but the portions bordering the arcuate bores extend over the corners of the lower, inturned, horizontal flanges, and fit snugly between such flanges and the table top, so that the bar when pressed into place is held snugly in place between the flanges and the table top.

With the improved construction referred to the joint bars can advantageously be operated upon in pairs for producing the spaces between adjacent blocks.' By clamping two joint bars in a jig or holder at a predetermined, uniform distance from one another, the bars can be fed together step by step beneath a boring tool. At each operation of the tool segments are cut from both joint bars, and this operation is performed in an espectially advantageous manner because the opposed'jointxbars serve to balance one another with respect to lateral thrusts exerted upon the boring tool.

. The boring tool desirably has a mechanically limited stroke and includes boring instruments of two diameters, the larger diameter tool being designed to reduce the marginal area adjacent the smaller bore to a thickness precisely equal to the space between the body portions of the channel members and the inturned lower flanges thereof. Whenthe several required cuts have been made in a pair of bars, the bars are reversed in the jig and the operation is repeated.

The improved construction can be produced far more economically than the construction which, it is designed to supersede. It has no dispart of this speciupon the line 2-2 of Figure I,- looking in the direction of the arrows;

Figure 3 is a view similar to Figure 2', taken upon the line 33 of Figure 1, looking, in the direction of the arrows;

Figure 4 is a vertical, transverse, sectional view, the section being taken upon the line 44 of Figure 5, looking in the direction of the arrows;

Figure 5 is a fragmentary,. horizontal, sectional view taken upon the line 5-5 of Figure 4,..1ookin in: the direction: of the arrows;

Figure 6 is a perspective view of an inverted joint bar which embodies features of the invention; and

Figure 7' illustrates a. pair of joint bars clamped together so that they may be operated upon simultaneously in. the boring of: the spaces between the side blocks of the bar.

The illustrative table I comprises two or more sections, of which. two sections, designated 2' and 3-, respectively, are illustrated. The several sections are essentially duplicates. of one another, and a description of the parts of one section. is, therefore, equally applicable to the parts oi? another. Each table section is des'h'a-biy made up of a series of longitudinal sheet metal channel bars 4., each comprising a plain central body portion 5, down-turned vertical side flanges 6, and inturned horizontal bottom flanges. I, The members are connected to one another by transverse tie members 8, 9 and to: in the form of sheet metal channel members. The. tie members a are located intermediate the ends of. a section and may be plain channelmembers. while the tie members 8 and I'll are located at opposite ends of a section, are of special construction, and will be described more fully hereinafter.

The table legs II may also be in the form at sheet metal channel bars, each having the end thereof: secured. in one of the channel: bars 8, 9, HI.

A surface sheet M of non-metallic material, desirably of the composition known commercially as Masonite," is adhered or: otherwise suitably secured to the top plane surface of the" table top formed by the body members 5. of the channel bars 4. Each sheet M at the end of. its table sec tion which is to be joined to another table sec.- tion is formed with a shouldered upper recess I5 to provide a reduced lower end portion I6. The end portion Ii6 terminates a little short oi the channel bars 4, so that if the surface sheet becomes loosened from the table top, the ends of the surface sheet can creep toward the end oi the table section without bulging.

A joint bar I! is interposed between the. ad-

jacent ends of the table sections 2 and 3 the her being desirably made of wood or non-.- mctallic composition which will. rovi'de a settle i:.;tory ii'crlzing surface. The bar I"! includes a con-*tmuous smooth head portion re and a continuous central body portion I'l'. The head pertion I8 projects to either side of the central body portion I9 to lie in the recesses I 5 of the surface sheets I4. The head portion I8 is of substantially the same depth as the recesses I5, and the smooth upper surface of the head I8 stands substantially flush with the upper surfaces of the surface sheets I4.

The side: faces of the head are: spaced? slightly from the adjacent vertical walls of therecesses I5, so as to admit of relative creeping of the surface sheets without buckling.

Beneath the plain body members 5 of the channel bars I which form the main body of the table tom thecentral body portion I9 of the joint bar F1 has progliecting from each of its sides a series of spaced side body parts 20. The side body parts 29. arespaced from one another to provide clearance for the side vertical flanges 6, the spacing being effected by removing arcuate segments of the material to leave segmental bores: it.

Each side:- body part 28: is separated from; the opposed. side: portion. or the head: It: by a slotor channel 22 at just sufli'cient width to receive and substantially fit the.- loody part 5 of a channel member 4, together: with the reduced emi portion to of the associated surface sheet It. The head part Ira and: the side body parts 20 do not exert any substantial& clamping or frictional forceupon the members 5 and 136,. but. they do hold. these members against separation. from one another. while permitting? relatives creep to occur with sub-F stantfal' fireedom.

Concentrically with the segmental bores. ZI; additional: segmental bores. 23 of larger diameter but. of. less; depth are: formed.

Desirabty av single boring tool: is: provided for making both ofv the bores, and the penetration of this tool'- is mechanically limited so that. the smaller bore will not. be extended into the head portion m of the Joint bar I"! and so that the base. of the larger here. willbe separated from the lower boundary oi. the slot. 22 by a distance exactly equal? to the: space between a flange 'I and the; both part 5. of a. channel member 4.

The formation of the relatively diameter bores reduces: the bar thickness to provide. re:- ions of minimum thickness adapted to between. the side flanges E of adjacent table sec tious. Since this region of mininmm thickness is. of extreme-by lengthwise extent the flanges I do not fit into the spaces between the side body members: 2d but instead engage. the surfaces 24 which constitute the bases of the larger diameter bore 232.. The body members 29 are thus fitted. snugly between the parts. 1 and 5 of. the channel members; 4 at the corners of the flanges t.

The bores 2t and 23 are formed in an extremely and economical manner by the procedure illustrated in. Figure 7. Two. of the cars H are clamped together with spacer blocks 25 of predetermined thic-kuess. placed between them.

The particuiar ctamping' device employedis not important so long as it is suitable for clampirrg and maintainin the two bars at the proper distance from one: another. U-shaped clamps 2d are. illustrated. Through one arm 27 a screw 2& is threaded which carries a clamping plate 28. Turning. oi; the: screw 28 clamps the assembled bars and interposed spacer block firmly together. The two bars thus associated are subjected togather to the action or the two-diameter boring toof. so that each has the series of bores 2| and 3 formed in it at the side which faces toward the other bar. When the several segmental bores have been formed, the bars are interchanged as to position and again subjected together to the action of the borin tool for forming the remaining bores and completing the two bars.

As illustrated, each table section has at the lefthand end thereof one of the tie members 8 and at the right hand end one of the tie members l0. These tie members are secured to horizontal flange members 1 in any suitable manner as y screws 30. The tie member comprises a vertical flange 3|, a horizontal bod portion 32, a vertical flange 33, and an inturned horizontal flange 34 at the lower extremity of the flange 33. The tie member 8 comprises a right hand vertical flange 35, a central horizontal body portion 36, a left hand vertical flange 31, and an outturned horizontal flange 38. The tie member 8 extends across the space intervening between the two table sections which is bridged by the central body portion IQ of the joint bar l1.

When the joint bar and table sections have been fitted together substantially as illustrated in Figures 1, 2, 3 and 5, bolts 39 are passed through the flanges 33 and 31 and the flanges are drawn and clamped together by threading nuts 4| onto the bolts 39. Bolts 42 are also passed downward through the flanges 34 and 38. Nuts 44 are threaded on the bolts 42 and clamp the flanges 34 and 38 together.

With the construction described, table sections may be conveniently and efliciently united and separated as conditions may require. The joint bar is clamped between the adjacent ends of the table sections, and it serves to hold the ends of the section tops and of the surface sheets in smooth contact with one another at all times. The joint bar is not subjected to any substantial strain, either during manufacture, assembly, or use. It performs its intended function in a very efficient and dependable manner at all times.

I have described what I believe to be the best embodiment of my invention. I do not wish, however, to be confined to the embodiment shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. A joint bar of non-metallic material for table joints, comprising a continuous central body portion, a continuous head portion projecting outward at both sides from the central body portion, and a series of side body portions at spaced intervals along opposite sides of the central body portion, said side body portions being separated from the continuous head portion by channels of substantially uniform width, and the successive side body portions being separated from one another by spaces each of which has the shape of a cylinder segment.

2. A joint bar of non-metallic material for table joints comprising a continuou central body portion, a continuous head portion projecting outward at both sides from the central body portion, and a series of side body portions at spaced intervals along opposite sides of the central body portion, said side body portions being separated from the continuous head portion by channels of substantially uniform width, and the successive side body portions being separated from one another by spaces each of which has the shape of a cylinder segment, the side body portions being reduced to predetermined thickness in arcuate areas bordering upon and concentric with the segmental spaces.

PHILIP ROSENBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 855,813 Roth June 4, 1907 1,423,949 Laughlin July 25, 1922 1,444,798 Laughlin Feb. 13, 1923 1,640,377 Scherer Aug. 30, 1927 1,855,273 Adams Apr. 26, 1932 1,893,481 Adams Jan. 10, 1933 1,976,969 Soukup Oct. 16, 1934 2,053,462 Chaplin Sept. 8, 1986 2,166,195 Rosenberg et a1 July 18, 1939 2,166,196 Rosenberg July 18, 1939 2,275,943 Bayley Mar. 10, 1942 2,280,094 Madsen Apr. 21, 1942 2,327,743 Rosenberg Aug. 24, 1943 2,396,008 Hazel, Jr. Mar. 5, 1946 2,414,623 Battin Jan. 21, 1947 

